package com.qingcheng.pojo.order;

import java.util.HashMap;

/**
 * @ProjectName: qingcheng_parent
 * @ClassName: test
 * @Time: 2019/7/3
 * @Author: zhou24
 * @Description:
 * @Experience:
 */
public class test {
    public static void main(String[] args) {

        HashMap<String, String> map = new HashMap<>();
        map.put(null,null);
        System.out.println(map.size());
    }
}
